Method Detail

getKey

Retrieve the first item from the first map, assuming that there is just
one item and just one map, and that the item is a number.
This is the typical case: a single, numeric generated key.

Keys are held in a List of Maps, where each item in the list represents
the keys for each row. If there are multiple columns, then the Map will have
multiple entries as well. If this method encounters multiple entries in
either the map or the list meaning that multiple keys were returned,
then an InvalidDataAccessApiUsageException is thrown.